Referring to FIG. 1, U.S. Pat. No. 5,852,397 disclosed a conventional surface-mounted PTC circuit protection device 1 which can be mounted on a substrate 9 (such as a circuit board). The PTC circuit protection device 1 includes a PTC component 13, a first electrode portion 11, and a second electrode portion 12, a first conductive portion 14, and a second conductive portion 15. Further, plating layers 18 are formed on the first and second electrode portions 11, 12 and the first and second conductive portions 14, 15.
To mount the aforementioned device 1 on top of the substrate 9, the plating layers 18 of the conventional surface-mounted PTC circuit protection device 1 is directly placed on and soldered to the substrate 9. However, such design may be disadvantageous for heat dissipation of the substrate 9 and the PTC circuit protection device 1. Thus, the PTC circuit protection device 1 may have inferior operating efficiency which may cause damage due to overheating.